/**
* br_extract_prefix:
* path: The full path of an executable or library.
* Returns: The prefix, or NULL on error. This string should be freed when no longer needed.
*
* Extracts the prefix from path. This function assumes that your executable
* or library is installed in an LSB-compatible directory structure.
*
* Example:
* br_extract_prefix ("/usr/bin/gnome-panel"); --> Returns "/usr"
* br_extract_prefix ("/usr/local/lib/libfoo.so"); --> Returns "/usr/local"
* br_extract_prefix ("/usr/local/libfoo.so"); --> Returns "/usr"
*/
char *
br_extract_prefix (const char *path)
{
const char *end;
char *tmp, *result;
br_return_val_if_fail (path != (char *) NULL, (char *) NULL);
if (!*path) return strdup ("/");
end = strrchr (path, '/');
if (!end) return strdup (path);
tmp = br_strndup ((char *) path, end - path);
if (!*tmp)
{
free (tmp);
return strdup ("/");
}
end = strrchr (tmp, '/');
if (!end) return tmp;
result = br_strndup (tmp, end - tmp);
free (tmp);
if (!*result)
{
free (result);
result = strdup ("/");
}
return result;
}
/**
* br_locate:
* symbol: A symbol that belongs to the app/library you want to locate.
* Returns: A newly allocated string containing the full path of the
* app/library that func belongs to, or NULL on error. This
* string should be freed when not when no longer needed.
*
* Finds out to which application or library symbol belongs, then locate
* the full path of that application or library.
* Note that symbol cannot be a pointer to a function. That will not work.
*
* Example:
* --> main.c
* #include "prefix.h"
* #include "libfoo.h"
*
* int main (int argc, char *argv[]) {
* printf ("Full path of this app: %s\n", br_locate (&argc));
* libfoo_start ();
* return 0;
* }
*
* --> libfoo.c starts here
* #include "prefix.h"
*
* void libfoo_start () {
* --> "" is a symbol that belongs to libfoo (because it's called
* --> from libfoo_start()); that's why this works.
* printf ("libfoo is located in: %s\n", br_locate (""));
* }
*/
char *
br_locate (void *symbol)
{
char line[5000];
FILE *f;
char *path;
br_return_val_if_fail (symbol != NULL, NULL);
f = fopen ("/proc/self/maps", "r");
if (!f) {
if (fallback_func)
return fallback_func(symbol, fallback_data);
else
return NULL;
}
while (!feof (f))
{
unsigned long start, end;
if (!fgets (line, sizeof (line), f))
continue;
if (!strstr (line, " r-xp ") || !strchr (line, '/'))
continue;
sscanf (line, "%lx-%lx ", &start, &end);
if (symbol >= (void *) start && symbol < (void *) end)
{
char *tmp;
size_t len;
/* Extract the filename; it is always an absolute path */
path = strchr (line, '/');
/* Get rid of the newline */
tmp = strrchr (path, '\n');
if (tmp) *tmp = 0;
/* Get rid of "(deleted)" */
len = strlen (path);
if (len > 10 && strcmp (path + len - 10, " (deleted)") == 0)
{
tmp = path + len - 10;
*tmp = 0;
}
fclose(f);
return strdup (path);
}
}
fclose (f);
return NULL;
}
/**
* br_prepend_prefix:
* symbol: A symbol that belongs to the app/library you want to locate.
* path: The path that you want to prepend the prefix to.
* Returns: The new path, or NULL on error. This string should be freed when no
* longer needed.
*
* Gets the prefix of the app/library that symbol belongs to. Prepend that prefix to path.
* Note that symbol cannot be a pointer to a function. That will not work.
*
* Example:
* --> The application is /usr/bin/foo
* br_prepend_prefix (&argc, "/share/foo/data.png"); --> Returns "/usr/share/foo/data.png"
*/
char *
br_prepend_prefix (void *symbol, const char *path)
{
char *tmp, *newpath;
br_return_val_if_fail (symbol != NULL, NULL);
br_return_val_if_fail (path != NULL, NULL);
tmp = br_locate_prefix (symbol);
if (!tmp) return NULL;
if (strcmp (tmp, "/") == 0)
newpath = strdup (path);
else
newpath = br_strcat (tmp, path);
/* Get rid of compiler warning ("br_prepend_prefix never used") */
if (0) br_prepend_prefix (NULL, NULL);
free (tmp);
return newpath;
}
/**
* br_locate_prefix:
* symbol: A symbol that belongs to the app/library you want to locate.
* Returns: A prefix. This string should be freed when no longer needed.
*
* Locates the full path of the app/library that symbol belongs to, and return
* the prefix of that path, or NULL on error.
* Note that symbol cannot be a pointer to a function. That will not work.
*
* Example:
* --> This application is located in /usr/bin/foo
* br_locate_prefix (&argc); --> returns: "/usr"
*/
char *
br_locate_prefix (void *symbol)
{
char *path, *prefix;
br_return_val_if_fail (symbol != NULL, NULL);
path = br_locate (symbol);
if (!path) return NULL;
prefix = br_extract_prefix (path);
free (path);
return prefix;
}
/* Emulates glibc's strndup() */
static char *
br_strndup (char *str, size_t size)
{
char *result = NULL;
size_t len;
br_return_val_if_fail (str != NULL, NULL);
len = strlen (str);
if (!len) return strdup ("");
result = (char *) calloc (sizeof (char), len + 1);
memcpy (result, str, size);
return result;
}
/**
* br_extract_dir:
* path: A path.
* Returns: A directory name. This string should be freed when no longer needed.
*
* Extracts the directory component of path. Similar to g_dirname() or the dirname
* commandline application.
*
* Example:
* br_extract_dir ("/usr/local/foobar"); --> Returns: "/usr/local"
*/
char *
br_extract_dir (const char *path)
{
char *end, *result;
br_return_val_if_fail (path != (char *) NULL, (char *) NULL);
end = strrchr (path, '/');
if (!end) return strdup (".");
while (end > path && *end == '/')
end--;
result = br_strndup ((char *) path, end - path + 1);
if (!*result)
{
free (result);
return strdup ("/");
} else
return result;
}
